Acoustic device.



R. WHITMAN.

ACOUSTIC DEVICE.

APPLICATION FILED DEC-23,1914.

Patented Apr. 24, 1917.

RANDOLPH WHITMAN, OF MOUNT VERNON, NEW YORK.

ACOUSTIC DEVICE.

Specification of Letters Patent.

Patented Apr. 24, 1917.

Application filed December 23, 1914. Serial No. 878,688.

To all whom it may concern:

Be it known that I, RANDOLPH \VHrrMAN, a citizen of the United States,residing at Mount Vernon, ()akwood Heights, in the county of Vestchesterand State of New York, have invented certain new and useful Improvementsin Acoustic Devices, of which the following is a specification,reference being had to the accompanying drawmg.

This invention refers to acoustic devices, and more in particular tothose used to modify, change or regulate the sound produced inartificial apparatus.

Some of the main objects of this invention are To produce a device forremoving metallic and other objectionable extraneous sounds from soundtransmitting apparatus.

To provide means for modifying the tone of transmitted sound, to adesirable extent.

To provide means for bringing transmitted sounds directly to the earmechanism of a hearer, and to the exclusion of extraneous sounds.

To provide means for filtering artificially transmitted sounds so thatthey will appear to the bearer in their normal values.

To provide means for eliminating or absorbing high tones, and nervestraining sounds before the ear is reached.

To provide means for making the conversation over telephone lines andthe like, more distinct and agreeable.

Other objects will become apparent as the invention is more fully setforth.

Many devices have been used to eliminate the difficulties or objectionsmet with in transmitted sound practice and this has been particularlynoticeable in connection with telephone receivers. Rubber caps have beenused, over the diaphragm end of receivers, but in every case they haveimpeded the action of the sound waves arising from the receivers, so asto make their use objectionable. In apparently every case, efforts havebeen directed to keep out extraneous sounds, rather than improve orchange the sound in question itself. This invention is directed towardthe sound as it comes from the receiver or other apparatus, and takingthe soum it converts it mainly by means of a cushion, into tones moresuitable to the bearer or the purpose.

In the drawings, which show by way of example, an embodiment of thisexample:

Figure l is a view in perspective showing the device embodying thisinvention, applied to a telephone receiver.

Fig. 2 is a sectional view of the device.

Fig. 3 is a plan view of the device.

Fig. 4 shows a modification of thediaphragm which is not perforated.

Fig. 5 shows a modification with a plurality of holes in its diaphragm.

Fig. 6 shows a modification of the device with a plurality ofdiaphragms.

Similar reference characters refer to similar parts throughout thedrawings.

In the construction shown in the drawings, the reference character 1represents a tele phone receiver and on which is mounted a device 2,which consists of a ring like body having both ends 3 and i turnedinwardly.

The body swells out at the end 3 so as to give a quasi-megaphone shape,and the other end 4.- is arranged to closely embrace the telephonereceiver under its cap. The body is preferably constructed of stiff yetsubstantially flexible material such as rubber of semi-hardness.

A diaphragm 5 of very flexible and elastic material (such as gumelastic, or that which lay balloons are constructed of) is secured msideof the body in a suitable manner, and may be made integral therewith ifdesired. It is not desired, however, to limit the diaphragm or body ofthe device construction to any particular material.

The diaphragm is so placed is the body that it will preferably close theend of the receiver adjacent to the diaphragm of the latter so the soundwaves from the same will efficiently act upon the diaphragm 5 in thedevice. It is also preferred to have the diaphragm 5 perforated, asshown at 6. In perforating the diaphragm it is preferable to avoidlocations in the same, where the effective elasticity of the diaphragmmight beaffected or Where the maximum waves effect is found or known totake place from.

The diaphragm 5 is of course made taut in the body. The amount of theperforating can be arranged to suit the circumstances as well as thenumber of the diaphragms. For ordinary usage on a telephone receiver itis preferable to use only one diaphragm with a slight perforation.

In operation, the sound waves from the apparatus, in this case thediaphragm of the receiver, impinge upon the diaphragm 5 of the device,and the air being contained and elastic, a cushion and filter isprovided for the sound. The diap 5 then conveys the sound, but withaless amplitude thereby lowering the tone of the sound and improving itstimbre. The sound at last acts upon the ear which is held against theend 3, and surges back and forth from the device d aphragm, acting inquasi-unison therewith and practically directly from the diaphragm. Theform of the end 3 serves to exclude extraneous sounds, and its material,being relatively flexible, offers no shock to the ear.

While but one general form and use of this invention is shown in thedrawings, it is not desired to limit this application for patent to thesame, or in any other way otherwise than limited by the prior art, asmany forms of construction 0 this invention may be made withoutdeparting from the principles thereof, and coming within the scope ofthe appended claims.

Having thus described the invention, what is claimed is:

1. In combination with a sound giving device, a very flexible perforateddiaphragm, and flexible means adapted to connect the diaphragm with thedevice and adjacent to its sound giving part, and means for deliveringsound waves directly to the ear of a user, when said diaphragm is actedupon by the sound waves from said device.

2. In combination with a sound giving device, very flexible erforateddiaphragm means, means for fl dxibly connecting the diaphragm means tothe device and adjacent to the sound giving part, and means provided forpermitting sound waves to pass directly through the diaphragm means.

3. In combination with a sound device, an attachment comprising a holderadapted to embrace a portion of the sound device, a perforated diaphragmtransversely disposed in the holder, and having a perforation thereinfor indicating-the proper tension of the diaphragm and the position ofthe holder on the device.

4:. In combination with a telephone resoften the tone of sounds comingfrom the receiver without apparently reducing theirforce. I,

5. In combination with a telephone receiver, an attachment comprising aninclosed holder adapted to cup over the receiver, a centrally disposedelastic diaphragm means in theholder arranged between the receiver shelland the outer o nin gl of the holder whereby a cushion 0 air W1 beprovided on both sides of the diaphragm and the diaphragm will also actas a cushion so that the sounds from the receiver will be modified.

6. An attachment for telephone receivers comprising in combination, asoft rubber receiver-inclosing member having rolled inclosing edg:aortions and its outer portion inwardly li mouthed, a relatively smallelastic diaphragm integrally connected to the bell-mouthed portion ofthe said memher and centrally arranged with respect to the member, and aperforation centrally arranged in the diaphragm, said perforation beingso flexibly held y the member that the stress put thereon will causesuch variation in the form of the perforation as to indicate the actionof the attachment on the sound waves acting and passing therethrough.

7. An elastic ear piece having 2. diaphragm permanently secured theretoada ted to be stretched over the ear piece of a telephone receiver and aquasi-megaphone projection for engaging the head of the user.

In testimony whereof I hereunto aflix my signature in the presence oftwo witnesses.

RANDOLPH WHITMAN.

Witnesses:

E. W. DAVIDSON, STUART R. WHITMAN.

race the receiver, 50

